Conventionally, the discharge lamp and the laser oscillator are used as a light source, and the lighting device with the light source is produced. Recently, in order to achieve the low consumption of the electrical power and to improve the operating time of the lighting device, the LED unit with the LED modules (light emitting diode module) is produced instead of the discharge lamp.
The LED module comprises an LED chip and a package which houses the LED chip. The LED modules used to be combined with each other to produce light having an amount same as an amount of the prior lighting device such as discharge lamp. Japanese patent application publication No. 2004-528698A discloses the LED module which comprises a plurality of the LEDs. The LED module comprises the LEDs each of which are disposed on the sub-mount member having an electrical insulation property; the sub-mount member is disposed on the spreader having a heat conductive material. Each one of the LEDs of the LED module is connected to an electrical contact through a wiring. Japanese patent application publication No. 2007-234571A discloses a lighting apparatus which comprises a plurality of lighting unit and a printed circuit. In the lighting apparatus, the lighting units and the printed circuit are mounted on the heat radiation plate through the electrical insulation film; the heat radiation plate is made of metal material; the electrical insulation film has heat conductivity. Each one of the lighting units has the LED and a transparent cover which covers the LED. In the lighting apparatus, each one of the LEDs is electrically connected to the printed circuit through the wire which is provided by the wire bonding.
However, each one of the LED module and the lighting apparatus mentioned in the above is provided with the sub-mount member which mounts the LED chip, is provided with no LED module which is directly mounted on the heat radiation plate. In addition, the LED module requires the bonding wire for establishing the electrical connection with respect to the circuit of the substrate. The fact of employing the bonding wire causes the increase of the component count, and requires the great care. This results in the increase of the manufacturing cost. In addition, when manufacturing the LED module, there is a possibility of the breakage of the wire bonding due to the contact with respect to something.